Here's the Max Payne 1 info that you requested although i'm a bit confused as to why you would want to mod for a old game engine like Max Payne 1 when it seems that you have a Half-Life 2 mod on the go under your mods section?, but anyway, it's always good to see a new modder comming over to the Max Payne community....;)

The best place to find virtually all the tools, tutorials & mods that your ever need for modding for Max Payne 1 is from Max Payne 1 downloads section at L4Y , here's the link:

And as for prefabs, well you won't find many ( if any ), on the web now days but I myself have a personal stash of prefabs that i've collected over the years form various web sites that are now closed.
Here's the links where you can download the zip files containing these prefabs. There are 3 zip files in total: